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-   -   Sony Z7 auto focus problem (https://www.dvinfo.net/forum/sony-hvr-z7-hvr-s270/128875-sony-z7-auto-focus-problem.html)

Anthony Smith August 27th, 2008 10:38 PM

Sony Z7 auto focus problem
 
The auto focus for this camera is really slow and NOT good compare to Sony Z1 or Sony PD170

Is this problem fixed or is Sony going to fix this problem? If so, when?

John Knight August 27th, 2008 11:25 PM

It's a pro camera, pro lens. Much different to auto models.

Noa Put August 28th, 2008 02:14 AM

Antony, I think what John was trying to say was that the autofocus handles differently on every camera and that the best way to get good focus is to go manual.
I don't have a z7 but if it has the option you could put it in manual and hit the "one push focus" button, in that way the focus will not start hunting in darker area's. I do rely on the autofocus quite a lot in run and gun situations and there is nothing wrong with that, I only use it though in good light conditions and when the lens is wide. Once I zoom in or when it gets too dark I go manual and use the one push focus button to focus right and then leave it at that. I found that working with HD the focussing can be quite tricky but the button for instant focussing has been a great help for me.
So I think you will have to find a way to deal with the slower autofocus response because every camera deals with it in another way.

And John, the reason why I like this forum so much is that you always get an answer and everybody treats you with respect, even with "stupid" questions. About 2 years ago I asked a simple audio related question about the dvx100 on the dvxuser forum and I got the same "we're sick and tired of these questions" replies as you did. It's this kind of attitude that will scare people away from a forum. Think that everybody is learning here and you have to realize that before you answer.

Tom Hardwick August 28th, 2008 03:00 AM

I think John Knight's answer is unhelpful to say the least. There's no such thing as a professional camera, only professional people. A professional's just as likely to use an A1E as a Z1 as an EX1 - it depends on what's needed on the shoot.

Anthony - I think you need to get your Z7 checked out if it's a big concern. A / B testing it alongside another Z7 would be an excellent way to see if your camera does indeed need looking at. As a bottom line, the auto-focus should be faster than manual by at least 50% - it knows which way to turn the ring and it won't need to rock 'n' roll when it gets there. Even with peaking we rock 'n' roll - it's only human nature.

Sony aren't in the habit of stepping backwards, and technological progress means that every generation betters the one before. On this assumption I'd say the Z7 should be doing everything at least equal to the Z1 and in some cases better, and I'd include their auto-focus speed and accuracy in this.

Check it out though. Sony camcorders are taking a few hits these days as they try to overdo the market penetration.

tom.

Wacharapong Chiowanich August 28th, 2008 03:28 AM

Quote:

Originally Posted by Anthony Smith (Post 925927)
The auto focus for this camera is really slow and NOT good compare to Sony Z1 or Sony PD170

If so, when?

Anthony, what was the shooting mode or frame rate you autofocused in? Autofocus in 30p, 25p and 24p is always slower than in 60i or 50i, other factors being equal. Both Canon XL-2 and Panasonic DVX-100 series have trouble autofocusing in 24p and 25p as well. Though I'm not an engineer, it's quite safe to say that autofocus speed is dependent on the recording frame rate and probably the scanning method also.

Wacharapong

Uli Mors August 28th, 2008 04:15 AM

Focus Ring Z7
 
Hi there,

I am a XDCAM HD user , for handheld work I rented a Z7 for some wedding dancing etc.

I also used a Z1 sometimes, and I am considering a cam like Z1/Z7 for the future.

I experienced some odds IŽd like to know more about:

a) Is there a fast way to manually switch between Daylight and Tungsten?

b) I found the manually focus (mechanical focus) ring to be not really smooth. from Pro-Lenses I am used to adjust focus minimally (following a subject in Tele for instance) with the thumb or small finger. On the Z7 you need some certain strength to move the ring, more than on a Z1. This often leds to some vibrations or the fact that I had to handle the camera different. Sometimes focus simply jumped to far. What are your experiences?

c) From pro lenses I am used to some depth of field algebraics. With Z7 they seem to differ. Usually I zoom in, focus and zoom out. Usually I get the object focussed + a certain area behind. With Z7 I often got the impression, that in WIDE the subject doesnt stay sharp & focussed. Whats your experience?

d) In shooting situations I more as once switched from mechanical to servo focus mode incidentally. I am wondering if there would be a way to avoid that (I considered a strap around the lens to prevent the wrong mode)


In the end I like the Z7 much, though the display is a bit small. Ergonomically I like the Z1 too, its not as heavy, but has no manual (mechanical) focus.

ULI

Tom Hardwick August 28th, 2008 04:25 AM

Quote:

Originally Posted by Uli Mors (Post 926026)

a) Is there a fast way to manually switch between Daylight and Tungsten?ULI

Yes. On the Z1 the assign buttons can be easily programmed. You leave the W/B in the daylight mode and button 5 (say) you push 5 times to reach the indoor colour temp. The good thing is you can stop anywhere in between buttons 5 & 6 to fine-tune the w/bal - useful if you enter a room lit with lamps and daylight.

The Z1 does have manual focus but it's a servo action. The Z7 is better in that you can have zebras and peaking both on at the same time, with the Z1 you have to choose between them. I choose zebras.

tom.

Barry Wilkinson August 28th, 2008 04:37 AM

Hi Uli,
a I have a 270 which has the same lens as the Z7
I am used to a DSR 570 with "normal " set up of buttons. On that you have a preset for w/b and it changes depending on which colour filter is in, so you have tungsten and daylight available all the time. I have only found a way of storing one preset on my 270( unless anyone knows another way) I store tungsten on the grounds that daylight varies a lot more. Having said that , after years of religiously doing white balances manually on virtually every shot I now leave it on AUTO white unless I can see that the mixed colour light will cause problems with face colour. I use fixed tungsten on things like bands where the light can change colour every second. It works well so far!
I find the assign buttons a bit of a pain because they are so easy to switch by accident and I cam never remember what function I put on them. They need to have a more positive locking action like other buttons on the body.
b I agree the focus ring is not very precise compared with a more pro lens. I think it is made worse by the fact that the ring is smaller so you can get large focus changes from small input. Also I have been used to a very sharp tubed eyepiece on the 570 which allowed you to accurately follow focus in close up of someone walking towards you. The eyepiece on the 270 is colour/lcd and basically not as good as it should be!
d It is very easy to push the focus ring forward and go into auto focus by accident. As a confidence booster I just keep trying to find the mechanical end stops when in manual...if the ring keeps turning I know its in auto.
c Not sure unless your lens isnt holding focus through its range( back focus problem?)

Anthony Smith August 28th, 2008 04:47 AM

thankyou all for the reply including John Knight.

As an event videographer, we don't have the luxury of take 2 , take 3 , take 4 ...... etc.
There is no such thing as take 2 infact.

I want to buy Z7 camera but when tested on the demo camera, the auto focus is worst (quite bad) than z1 or pd170 or Fx1. Just want to know why is that so and is Sony going to fix it or not.

EX1 is an exellent camera but 1 card cost over $1000 dollars is out of the question at this stage.

Hoping for a reply from Sony people about Z7 auto focus problem.

Sean Seah August 28th, 2008 06:04 AM

Hi Anthony, I upgrade from the FX1 to EX1 n I have to inform u that the auto focus on the EX1 sucks big time too. I shoot events like u n end up going manual all the way! Other than that, the EX1 is a superb cam for the price pt.

Anthony Smith August 28th, 2008 06:37 AM

Quote:

Originally Posted by Sean Seah (Post 926051)
Hi Anthony, I upgrade from the FX1 to EX1 n I have to inform u that the auto focus on the EX1 sucks big time too. I shoot events like u n end up going manual all the way! Other than that, the EX1 is a superb cam for the price pt.

hi, i tested EX1 and the auto focus is very good compare to Z7. I like Z7 because it can shoot in many formats and on CF cards or tape.

However Z7 is not suitable for filming weddings because of the auto focus problem.

Tom Hardwick August 28th, 2008 07:05 AM

'However Z7 is not suitable for filming weddings because of the auto focus problem.'

That's quite a sweeping statement to make Anthony and I'm pretty sure Sony aimed this camera right at the run 'n' gun market - and this hits weddings fair and square.

The Z1 is superb for weddings (I know, I shoot lots of them) so I'd be mighty surprised to find the Z7 was a no-go.

tom.

Uli Mors August 28th, 2008 07:53 AM

since I put my vx2000 in manual (focus servo) mode on weddings too, I think some practising will help using the z7 too. I used it on some wedding videos and so far only complain about the focus ring, which doesnt turn as easy as a pro lens does.

ULi

Hedley Wright August 28th, 2008 09:19 AM

Quote:

Originally Posted by Anthony Smith (Post 926057)
However Z7 is not suitable for filming weddings because of the auto focus problem.

I've been using a Z7 all year and find it eminently suitable for weddings. Autofocus (on the relatively few occasions I use it) is just fine, true manual focus is great and I've also assigned push auto to the L2 button next to the grip for servo manual mode. My only gripe is with the LCD which doesn't work well outdoors.

Tom Hardwick August 28th, 2008 09:54 AM

Hedley - I find the Z1's top screen just fine out in the mid-day sun, though I admit to reading the zebras in these conditions. Surely the Z7's screen must be as good?


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